Lead is used in various industrial and consumer applications, including lead-acid batteries, photovoltaic solar installation, telecommunications equipment, computer systems, and electric vehicles. The most common application by far, however, is its use in lead-acid batteries. Approximately 80% of lead mined in the world is used in battery applications. Around 60,000 to 70,000 people are employed worldwide in the battery manufacturing industry and are directly exposed to lead.
When the concentration of lead builds in the body, it can cause serious health-related issues such as headaches, irritability, reduced sensations, aggressive behavior, difficulty in sleeping, anemia, constipation, and poor appetite. Furthermore, children exposed to lead can suffer kidney damage, hearing loss, loss of developmental skills, behavior attention problems, and reduced intelligence quotient (IQ). It is therefore critical to be able to detect the presence of lead contaminants to limit such exposure.
Lead contaminants can be detected using various techniques, including atomic absorption spectrometry (AAS), inductive coupled plasma mass spectrometry (ICP-MS), inductive coupled plasma atomic emission spectrometry (ICP-AES), dynamic light scattering (DLS), enzyme-linked immunosorbent assays (ELISAs), reversed-phase high-performance liquid chromatography coupled with UV-Vis or fluorescence detection, voltammetry, and fluorimetric techniques. Unfortunately, each of these techniques is time consuming, labor intensive, and requires a professional to perform the testing. In addition, many of these techniques require expensive instruments. In view of these drawbacks, the test most commonly applied in lead-acid battery factories is a swipe test in which the exposure of the skin to lead contaminants is determined by wiping the skin with a patch and applying a compound to the patch that reacts with the lead. In some detection kits used at such factories, sodium sulfide is applied to the patch, which turns yellow when lead ions are present in a concentration of approximately 1 to 3 parts per million (ppm) and turns dark when lead ions are present in a concentration greater than 50 ppm. Other detection kits use a solution of sodium rhodizonate (C6H2O6.2H2O), which reacts with Pb+2 ions and forms a pink to red color because of the formation of lead rhodizonate. While such kits are simple and inexpensive, they lack standardization, do not provide highly accurate results, and can provide false positive results.
In view of the above discussion, it can be appreciated that it would be desirable to have a system and method for detecting contaminants, such as lead contaminants, that is simple, accurate, and inexpensive.